High-strength and high-hardness reinforced wear-resistant steel and manufacturing method therefor

Abstract

Disclosed in the present invention is high-strength and high-hardness reinforced wear-resistant steel, comprising Fe and inevitable impurities, and further comprising the following chemical elements in percentage by mass: C: 0.22-0.33%; Si: 0.10-1.00%; Mn: 0.50-1.80%; Cr: 0.80-2.30%; Al: 0.010-0.10%; RE: 0.01-0.10%; W: 0.01-1.0%; and at least one of MO: 0.01-0.80%, Ni: 0.01-1.00%, Nb: 0.005-0.080%, V: 0.01-0.20%, and Ti: 0.001-0.50%. In addition, further disclosed in the preset invention is a manufacturing method for the high-strength and high-hardness reinforced wear-resistant steel, comprising the steps of: (1) smelting and casting; (2) heating; (3) rolling; and (4) on-line quenching: wherein the cooling start temperature of primary cooling is (Ar3′+5)-(Ar3′+50)° C., M90<final cooling temperature<Bs, and the cooling speed is 2-15° C./s; and then performing air-cooling to room temperature.

1 . A high-strength, high-hardness reinforced wear-resistant steel comprising Fe and unavoidable impurities, wherein it further comprises the following chemical elements in mass percentages:
 C: 0.22˜0.33%, Si: 0.10˜1.00%, Mn: 0.50˜1.80%, Cr: 0.80˜2.30%, Al: 0.010˜0.10%, RE: 0.01˜0.10%, W: 0.01˜1.0%; and at least one of Mo: 0.01˜0.80%, Ni: 0.01˜1.00%, Nb: 0.005˜0.080%, V: 0.01˜0.20%, Ti: 0.001˜0.50%.   
     
     
         2 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein it comprises the following chemical elements in mass percentages:
 C: 0.22˜0.33%, Si: 0.10˜1.00%, Mn: 0.50˜1.80%, Cr: 0.80˜2.30%, Al: 0.010˜0.10%, RE: 0.01˜0.10%, W: 0.01˜1.0%; and at least one of Mo: 0.01˜0.80%, Ni: 0.01˜1.00%, Nb: 0.005˜0.080%, V: 0.01˜0.20%, Ti: 0.001˜0.50%; with a balance of Fe and unavoidable impurities.   
     
     
         3 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein the mass percentage of each chemical element satisfies: C: 0.22˜0.31%, Si: 0.10˜0.80%, Mn: 1.00˜1.80%, Cr: 1.10˜2.20%, Al: 0.010˜0.080%; or the mass percentage of each chemical element satisfies: C: 0.23˜0.31%, Si: 0.15˜0.80%, Mn: 1.10˜1.80%, Cr: 1.10˜2.00%, Al: 0.015˜0.075%; or the mass percentage of each chemical element satisfies: C: 0.23˜0.30%, Si: 0.15˜0.65%, Mn: 1.15˜1.80%, Cr: 1.15˜2.00%, Al: 0.015˜0.070%. 
     
     
         4 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein the mass percentage of the chemical elements has one or more of the following features: the content of C is 0.23˜0.28%; the content of Si is 0.15˜0.65%; the content of Mn is 1.05˜1.65%; the content of Cr is 1.25˜2.10%; and the content of Al is 0.035˜0.080%. 
     
     
         5 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein, in the unavoidable impurities, P is ≤0.030%, and/or S is ≤0.010%. 
     
     
         6 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein it has a microstructure of martensite+bainite+residual austenite+carbide. 
     
     
         7 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein the volume fraction of residual austenite is ≥5%, and the volume fraction of martensite is ≤90%. 
     
     
         8 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein it has a Brinell hardness of 400˜500 HBW, a tensile strength of 1200˜1600 MPa, an elongation of 10˜15%, and a Charpy V-notch longitudinal impact energy at −40° C. of >40 J. 
     
     
         9 . A manufacturing method for the high-strength and high-hardness reinforced wear-resistant steel according to  claim 1 , which comprises steps of:
 (1) smelting and casting;   (2) heating;   (3) rolling;   (4) on-line quenching: wherein an initial cooling temperature for primary cooling is: (Ar3′+5)˜(Ar3′+50)° C., M 90 <a final cooling temperature<Bs, and a cooling rate is 2˜15° C./s; then preforming air cooling to room temperature.   
     
     
         10 . The manufacturing method according to  claim 9 , wherein in step (2), a slab heating temperature is controlled at 1030˜1230° C. and held for 1-3 hours 
     
     
         11 . The manufacturing method according to  claim 10 , wherein in step (2), the slab heating temperature is controlled at 1030˜1180° C. 
     
     
         12 . The manufacturing method according to  claim 9 , wherein in Step (3), a rough rolling temperature is controlled at 930˜1180° C., and a finish rolling temperature is controlled at 870˜970° C. 
     
     
         13 . The manufacturing method according to  claim 12 , wherein in Step (3), the rough rolling temperature is controlled at 930˜1130° C., and a finish rolling temperature is controlled at 875˜945° C. 
     
     
         14 . The manufacturing method according to  claim 9 , wherein in Step (3), a rolling reduction ratio in the rough rolling stage is controlled at more than 35%, and a rolling reduction ratio in the finish rolling stage is controlled at more than 55%. 
     
     
         15 . The manufacturing method according to  claim 9 , wherein in Step (4), an initial cooling temperature for the primary cooling is (Ar3′+5)˜(Ar3′+45)° C., (M 90 +5° C.)<a final cooling temperature<(B s −15° C.), and a cooling rate is 2˜12° C./s. 
     
     
         16 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 2 , wherein the mass percentage of each chemical element satisfies: C: 0.22˜0.31%, Si: 0.10˜0.80%, Mn: 1.00˜1.80%, Cr: 1.10˜2.20%, Al: 0.010˜0.080%; or the mass percentage of each chemical element satisfies: C: 0.23˜0.31%, Si: 0.15˜0.80%, Mn: 1.10˜1.80%, Cr: 1.10˜2.00%, Al: 0.015˜0.075%; or the mass percentage of each chemical element satisfies: C: 0.23˜0.30%, Si: 0.15˜0.65%, Mn: 1.15˜1.80%, Cr: 1.15˜2.00%, Al: 0.015˜0.070%. 
     
     
         17 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 4 , wherein the mass percentage of the chemical elements has one or more of the following features: the content of C is 0.23˜0.28%; the content of Si is 0.15˜0.65%; the content of Mn is 1.05˜1.65%; the content of Cr is 1.25˜2.10%; and the content of Al is 0.035˜0.080%. 
     
     
         18 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 7 , wherein the volume fraction of residual austenite is 5˜15%, and the volume fraction of martensite is 60˜90%. 
     
     
         19 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 18 , wherein the volume fraction of residual austenite is 5.3˜12.0% or 5.5˜8.5%, and the volume fraction of martensite is 70˜88% or 77.5˜85.6%. 
     
     
         20 . The high-strength, high-hardness reinforced wear-resistant steel according to  claim 1 , wherein the high-strength, high-hardness reinforced wear-resistant steel has a yield strength of 800˜1000 MPa or 830˜980 MPa, and/or a yield strength ratio of ≤0.75 or ≤0.70.